One (and only), (only) just, individual, and lone are all synonyms for only. Also and never are antonyms of only. And here are 28 another word for only.
(only) just, as little as, at best, at most, barely, by a hair's breadth, by the skin of one's teeth, entirely, exclusively, hardly, narrowly, no longer ago than, no/not more than, not until, scarcely, solely, uniquely, and wholly are all synonyms for only.
Individual, lone, one (and only), only possible, single, sole, solitary, unique, and exclusive are all another word for only.
Only synonym page has a variety of synonyms that differ in length. 2 synonyms with 4, and 15 letters and 7 synonyms with 6, and 8 letters. 3 synonyms with 10 letters and 1 synonym with 11, 12, 13, and 20 letters. For a total of 25 another word for only.
She only wanted to help.
This is the only option.
He only eats vegetarian food.
They only arrived yesterday evening.
I only need five minutes.