Green’s Dictionary of Slang

excellent, wonderful, ‘out of this world’.

1986		Eble Campus Sl. Nov.
1997–2001		Online Sl. Dict. 🌐 stellar adj 1. very good, excellent; COOL, AWESOME. (‘That was some stellar movie we saw last night.’).
2001		OnLine Dict. of Playground Sl. 🌐 stellar adj. Similar to ‘amazing’, ‘awesome’, ‘mega’ etc. e.g. ‘That haircut is great – really stellar!’.