English
hostmask
From host + mask.
Proto-Indo-European *gʰóstipotis ‘master of guests’
Proto-Italic *hostipotis
Latin hospes ‘a host’
Old French oste ‘innkeeper’
Middle English hoste
English host
Proto-Indo-European *mosgʷ- ‘netting, mesh, knot, loop’
…
Proto-West Germanic *maskā ‘mesh, net’
Medieval Latin masca
Italian maschera ‘mask, disguise’
Middle French masque ‘a covering to hide or protect the face’
English mask
Today it means
noun On IRC, a partial address that matches a number of hosts.
Language periods are conventional ranges, not dates for this word.
Etymograph / hostmask