'prayer' originates from Old French, specifically the word 'preiere' (also spelled 'preiere'/'preiere'), ultimately from Latin 'precaria' (from 'precari' = 'to request, beg'), where 'prec-' related to 'request, entreaty'.

'prayer' changed from Old French 'preiere' into Middle English 'preiere'/'preyer' and eventually became the modern English word 'prayer'.

Initially, it meant 'a request or entreaty' (more generally a petition), but over time it evolved into the modern primary sense of 'communication with or petition to a deity' and related liturgical uses.