| URANO | From Greek for "heavens", a prefix used to denote the sky in various terms relating to astronomy (5) |
| DEMI | A prefix used to denote half; or, Brat Pack member Moore (4) |
| GLOSSARY | From "word needing explanation, language, tongue", a brief dictionary; or, an alphabetical lexicon of terms relating to a specific subject (8) |
| ECO | Prefix used to denote something environmentally friendly (3) |
| CHRISTMASTREES | It's all about search terms relating to annual growth (9,5) |
| MARSCANDYBAR | Snack to take to astronomy class? |
| AMSTERDAM | Various terms accepted by man to get capital |
| MINSTREL | Old harpist left various terms in production (8) |
| ONCEINABLUEMOON | Almost never related to astronomy! (4,2,1,4,4) |
| GEO | Greek-derived -graphy-starter or -logy-opener, aka a prefix used in combining form to denote "earth" (3) |
| ORGANO | A prefix used in chemistry relating to carbon-containing compounds (6) |
| ALPHA | Greek letter, used to denote the first in a series of items/categories (5) |
| EARLY | Morning work shift; or, a word used to denote the first vegetables to crop, such as new potatoes (5) |
| OMEGA | Greek letter used to denote the last entry in a series |
| LANDS | Often used to denote the length of Great Britain, from ... End to John o'Groats (4'1) |
| TEMPO | Italian word meaning 'time' used to denote the pace at which a piece of music should be played (5) |
| EULER | Mathematician who popularised notational conventions including i to denote the imaginary unit and e for the base of the natural logarithm (5) |
| BRINY | Colloquialism used to denote the sea (5) |
| ALIBI | Legal term relating to a suspect's whereabouts (5) |
| ULTRA | Latin prefix used to mean 'extremely' |
