'aspergillum' originates from Latin, specifically the verb 'aspergere,' where 'asper-'/the verb root meant 'to sprinkle' (from Latin components meaning 'to' + 'scatter/sprinkle').

'aspergilla' (as the plural of 'aspergillum') came into English via Medieval Latin 'aspergillum' and ecclesiastical Latin usage; the term was adopted into English usage in the context of Christian liturgy.

Initially it referred to the instrument used to sprinkle or scatter liquid (literally 'to sprinkle'), and over time its meaning has remained specialized to denote the liturgical holy-water sprinkler.