'often-observed' is a compound adjective formed from 'often' and 'observed'. 'Often' originates from Old English 'oft', meaning 'frequently', and 'observed' comes from Latin 'observare', meaning 'to watch over'.

'Often' evolved from Old English 'oft', and 'observed' from Latin 'observare', through Old French 'observer', into Middle English 'observe'.

Initially, 'often' meant 'frequently', and 'observed' meant 'to watch over'. The compound 'often-observed' retains the meaning of being frequently seen or noticed.