adv. 25B6; adverb
a highly dangerous substance : VERY, extremely, exceedingly, particularly, most, really, thoroughly, decidedly, distinctly, exceptionally, immensely, inordinately, singularly, extraordinarily; N. English right; informal terrifically, awfully, terribly, majorly, seriously, desperately, mega, ultra, oh-so, damn, damned; Brit. informal ever so, well, dead, jolly; N. Amer. informal real, mighty, awful; dated frightfully.
he was highly regarded : FAVOURABLY, well, appreciatively, admiringly, approvingly, positively, glowingly, enthusiastically.
slightly, unfavourably.