say it: slayn
slain is a noun and adjective meaning "people who have been slain (as in battle)". It carries 2 recorded senses.
people who have been slain (as in battle)
killed; `slain' is formal or literary as in "slain warriors"
“a picture of St. George and the slain dragon”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for slain come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.