In a way that expresses dissatisfaction or grievance; with a complaining tone or manner.
From 'complain' (Old French 'complaindre,' from Latin 'complangere' meaning 'to bewail together') + '-ing' (present participle) + '-ly' (adverb marker). The suffix chain transforms the verb into an adverb describing how something is done.
The '-ly' adverb suffix is so common we barely notice it, but it's one of English's most productive word-building tools—we can attach it to almost any adjective to create an adverb, which is why languages without this feature often need separate words.
Complete word intelligence in one call. Free tier — 50 lookups/day.