flamen

英 ['fleɪmen; 'flɑː-] 美 ['flemɛn]

flamen (n.): "ancient Roman priest," 1530s, from Latin flamen "a priest of one deity," which is of unknown origin, perhaps from PIE root *bhlad- "to worship" (cognates: Gothic blotan, Old English blotan "to sacrifice"). Also used from early 14c., in imitation of Geoffrey of Monmouth, in reference to ancient pre-Christian British priests. Related: Flamineous.
The old connection of flamen with Skt. brahman- is highly problematic, and has been dismissed by Schrijver. As WH surmise, the ending -en points to an archaism, probably a n[euter] noun "sacrificial act" which changed its semantics to 'priest'; for a similar shift, cf. augur "bird-observer" .... The only viable comparanda are found in [Germanic], but they show root-final (or suffixal) *-d~. [de Vaan]

2. Wearing cassock , a flamen was inspecting the detailed work in the sacrifice hall.: 祭司穿上法衣,到庙里去察看祭堂的各项准备工作.