phi ‧ lan ‧ derer /fəˈlænd ə rə, fɪˈlænd ə rə $ -ər/ BrE AmE noun [countable] old-fashioned
[ Date: 1800-1900 ; Origin: philander 'lover' (17-19 centuries) , from Philander name given to a lover on old plays, from Greek phil- 'loving' (from philos ; ⇨ ↑ -phile ) + aner 'man' ]
a man who has sex with many women, without intending to have any serious relationships ⇨ playboy
—philandering adjective
—philandering noun [uncountable]