Dear word sommelier: I’m at a friend’s place, and he’s made bobotie, and it’s really good. Should I say “This bobotie is awesome” or “This bobotie is fantastic”?
First of all, we must acknowledge that there is a certain set of people who will insist – quite vehemently – that neither is acceptable: that awesome can only mean “inspiring awe” and fantastic can only mean “characteristic of, or produced by, fantasy”. People of this set actually do have dictionaries, but if they look in them, they arrogate to themselves the right to declare the ones they disagree with (all of them, ultimately) wrong: only the “original” meaning of a word is correct, and by “original” they mean “etymological, as they understand it”. (In truth, awesome first meant “full of awe”, and only in the next century “inspiring awe”; the original term for that was awful, a word that picklepusses frequently use unreservedly in its much more modern meaning of “nasty”.)
But such people are among the most arrant fools in all of creation, and ought not to be heeded any more than one would heed an unknown petulant two-year-old’s admonitions. So let us proceed with reality. Reality does include the meanings mentioned above, to be sure, but it is not restricted to them.
The question you ask may reflect a shift in usage, though I’m not sure of it as yet. My friend Michelle remarked to me today that she had the sense that fantastic was overtaking awesome as a general adjective of enthusiastic approbation. This is quite difficult to assess objectively, as simple searches don’t sort semantically. In overall usage, fantastic has always been more common than awesome, but awesome is actually a newer word and has certainly increased in usage, reaching a soft peak around 1980 and holding fairly well since, if Google Ngrams are to be believed (and they do have their limitations!). A Google search for each does pick up twice as many hits for awesome, but wordcount.org places fantastic much farther up in the British National Corpus.
Awesome is the more bivalent of the words. It retains a more specific sense, and one may use it as such. When someone sings the hymn “How Great Thou Art” and pronounces “O Lord my God, when I in awesome wonder consider all the worlds Thy hands have made,” there’s no risk of its being taken to be like saying “when I in totally wicked wonder” or “when I in way bitchen wonder” or something like that. But within the context of colloquial usage, it has a very clear air of youthful informality. It became so common and bleached in its peak (from which it has not subsided too much) that I used to think of this version of it as ossum, a sort of verbal marsupial hanging by its tail in the midst of the sentence. Which awesome is wanted can readily be specified by surrounding words and their tone: which would you take truly awesome to mean (I would take it to mean “awe-inspiring”)? How about totally awesome (“really good” for me)?
While awesome has had this bleached usage only since the late-mid 20th century, however, fantastic has been in similar broad service since at least the 1930s – which is still recent, given its existence as a word since the 1400s. But any use of it to mean anything other than “really good” now is very likely to have an air of quaintness. In the more cultured spheres, wherein dwell such people as know Berlioz’s Symphonie Fantastique, the sense of phantasm and fantasy is likely more present, and that large set of people who have see the musical The Fantasticks will have that charming tale (and its memorable tunes) imprinted in their minds, but hoi polloi will more likely think of a brand of spray-on cleaning solutions, Fantastik. (Observe the effects of the k with or without c, too, though.)
For either of the words, of course, usage on TV and in movies will have a strong effect, and we may assume those were prime vectors of the ascendancy of awesome for approbation. Fantastic likewise gets used by some notable personalities, and I can recall an ad from a few years ago for a lottery that paid $1000 a week for life in which the protagonist exclaimed “Faaaaantastic!” on receiving each cheque.
And that takes us to the heart of the matter. The bleached sense of these words is fundamentally phatic, and relies strongly on expressive potential. Awesome allows the gaping “aw” to lead in, embodying an expression of awe, surprise, amazement, et cetera. It then closes off neatly with an unstressed second syllable. It works much better, rhythmically, with totally than fantastic does (try both and see what I mean). It’s a big, smooth, solid stroke.
Fantastic, on the other hand, has three syllables, the stressed one of which is the second – but the first may be stretched out and emphasized as well. Due to its rhythm, it is conducive to tmesis: you can slip in an expletive intensifier, as in fan-freaking-tastic, which is not done in a word such as awesome. So it is more flexible and extensible. Its sound is less full of round-mouthed amazement and more full of wide-mouthed joy, pride, or enthusiasm. It has voiceless stops and another fricative, giving it the éclat of fireworks.
Moreover, because fantastic is widely established as a simple term of strong approbation, it doesn’t carry with itself the air of “valley girl” or similar teen in-group-ness (of course it was an “in” term back in the ’30s, but that’s too far back to have influence now), and so there is less likely a sort of winkingness to its usage, at least currently.
In your case, given the rhythm of bobotie and of the sentence as a whole, I would incline towards fantastic. It also more likely carries a tone that is more ingenuous and sincere and less self-observing. It may seem a stronger term of approbation, mind you, and the shape of the mouth in awesome may seem more suited to a comestible, so you do have to go with your own immediate sense of the occasion. The truth of it is that usage in such matters is an art, not a science, and one may defensibly use either, for different taste sensations.
You will also, by the way, want to consider what term, if any, you will use for the blatjang that (I presume) has been served with the bobotie.