A very nice Tuesday puzzle. The theme was well-hidden for most of the solve, and it played more like a themeless, which, frankly, I prefer. Is it just me? Do people need these little themes to stay interested in puzzles? Do constructors like making them more than they like making themeless? What is driving it?? I mean, a great theme can make a puzzle better, but things like vowel progressions, things like this, where the last word of every theme can be connected somehow, and even circles, like yesterday's, well… they aren't all that exciting most of the time. You say, "Huh," and then you move on.
Anyway, today, the almost unexpected revealer PICKUP (47D: Learn … or a word that can precede the ends of 20-, 29-, 44- and 53-Across) finally gave this puzzle meaning and purpose, and there was much rejoicing. By some. I guess. No, that's too harsh. I liked it, really I did. I just wonder sometimes about why we need themes five out of seven days of the week.
But with or without the theme, this is a fine puzzle. It starts out on shaky ground with NES and OLE, but ELICIT (2D: Bring out) saves that NW corner, and then things generally PICKUP from there. PICAYUNE (6D: Paltry), ANIMATE (7D: Bring to life), and TENTHS (8D: Kind of a place to the right of a decimal) (somewhat tortured clue, but still I like it) are all lovely in the North, and there's more good fill scattered all around.
If Huygens liked "ALG," he will certainly also like PRECALC (9D: Advanced algebra class, informally), not to mention BIKINI (32D: Pageant wear, at times). CUTSINLINE, SWIZZLESTICKS, GIZMOS… it's crammed with good fill. I can swallow a lot more IMRE, APIA, and ETAL when a puzzle has so much ZIP. Nice job.