IPA: /ˌɛkspɪˈdɪʃəsli/
KK: /ɛkˈspɛdɪʃəsli/
In a way that is quick and efficient.
The team completed the project expeditiously to meet the deadline.
Expeditiously → It is formed from "ex-" (meaning out) and "pedis" (from Latin "pes", meaning foot) and the suffix "-ious" (meaning full of). The word "expeditiously" means in a manner that is full of speed or efficiency, as if moving quickly on foot.
Think of 'moving out' ('ex-') quickly on 'foot' ('pedis') — that's why expeditiously means doing something quickly.