a-one
1. [ adjective ] of the highest quality
Synonyms: super crack topnotch first-rate tiptop tops ace
Examples:

"an ace reporter" "a crack shot" "a first-rate golfer" "a super party" "played top-notch tennis" "an athlete in tiptop condition" "she is absolutely tops"

Related terms: colloquialism superior
2. [ adjective ] (informal) of the highest quality
Synonyms: super crack topnotch first-rate tiptop tops ace
Examples:

"an ace reporter" "a crack shot" "a first-rate golfer" "a super party" "played top-notch tennis" "an athlete in tiptop condition" "she is absolutely tops"

Related terms: superior