Synonyms of highly in English:

highly


See definition of highly

adverb

1‘a highly dangerous substance’

SYNONYMS
very, most, really, thoroughly, extremely, exceedingly, particularly, tremendously, hugely, greatly, decidedly, distinctly, exceptionally, immensely, eminently, supremely, inordinately, singularly, extraordinarily, vastly, overly
very much, to a great extent
Scottish unco
très
Northern English right
informal terrifically, awfully, terribly, devilishly, madly, majorly, seriously, desperately, mega, ultra, oh-so, too-too, stinking, mucho, damn, damned, too … for words
informal, dated devilish, hellish, frightfully
British informal ever so, well, bloody, dead, dirty, jolly, fair
North American informal real, mighty, powerful, awful, plumb, darned, way, bitching
South African informal lekker
archaic exceeding, sore
ANTONYMS

slightly

2‘he was highly regarded by his colleagues’

SYNONYMS
favourably, well, warmly, appreciatively, admiringly, approvingly, positively, glowingly, enthusiastically, with praise, with admiration, with approbation
ANTONYMS

unfavourably, disparagingly