While Erman and Grapow note an additional meaning of ꜣt as a ‘head ornament’, Gardiner convincingly argues that this is based on a misinterpretation of passages where it means ‘readiness to strike’. Gardiner also suggests that the ‘moment, time’ sense of ꜣt is not independent, but developed from the ‘readiness to strike’ sense by way of reference to the suddenness or speed of a strike. Allen instead takes the ‘moment’ meaning as primary, rendering the ‘readiness to strike’ sense as ‘moment of rage’.
This word is sometimes used in parallel to pḥtj(“strength”).
Lesko, Leonard, Lesko, Barbara (2002) A Dictionary of Late Egyptian, second edition, volume 1, Providence: B.C. Scribe Publications, →ISBN, page 1
Gardiner, Alan (1948) “The First Two Pages of the Wörterbuch” in The Journal of Egyptian Archaeology, Vol. 34, p. 13–15
James P[eter] Allen (2010) Middle Egyptian: An Introduction to the Language and Culture of Hieroglyphs, 2nd edition, Cambridge: Cambridge University Press, →ISBN, page 455.