'anticommercially' is built from the prefix 'anti-' (from Greek 'anti-' meaning 'against') + 'commercial' (from French/Latin roots related to trade) with the adverbial suffix '-ly'.

'anti-' (Greek) combined with Medieval/Modern English 'commercial' (from Old French 'commercial' < Latin 'commercium') produced 'anticommercial' in modern English usage, and the adverbial form 'anticommercially' was formed by adding '-ly'.

Initially elements meant 'against' (anti-) and 'trade' or 'commerce' (commercium); over time the compound came to mean broadly 'opposed to commercialism' and thus the adverb means 'in a manner opposing commercialism or commercial motives'.