cheerful, lively, and good-humoured

expressing, suggesting, or inspiring gaiety

informal extremely pleasant or agreeable

I fancy I do like slang. I think it's awfully jolly to talk about things being jolly — Trollope

Brit, euphem slightly drunk

(+ along) to put (somebody) in good humour, esp in order to gain an objective

informal (+ up) to make (somebody or something) more cheerful and lively

chiefly Brit an enjoyable excursion or a jollification

rumbustious Australians out for a jolly — Edward Heath