Expedient describes a convenient, practical option, not necessarily a fair or proper one. Expeditious simply means fast. A decision can be expedient without being expeditious, and a process can be expeditious without being especially expedient.
The core difference
Expedient is about convenience over principle, while expeditious is about speed.
- expedient — convenient and practical for reaching a goal, even if not the most honest choice: it was politically expedient to avoid the issue before the election.
- expeditious — done quickly and efficiently: the team gave an expeditious response to the complaint.
How to tell them apart
Both words trace back to the same Latin root, expedire, meaning to make ready or free up, which is why they look so alike. Over time they split in meaning: expedient kept the sense of a shortcut chosen for convenience, sometimes at the cost of doing things properly, while expeditious settled on plain speed and efficiency.
The mix-up usually happens in formal or business writing, where someone reaches for expedient when they actually mean the process was quick. A quick check: if you could swap in convenient or opportunistic, use expedient; if you could swap in prompt or speedy, use expeditious.
