Sometimes we have a concept which can be described with multiple words only. As far as I know, we use the word phrase to describe these multiple words. Can I use the word term if I want to talk about both single- and multi-word definitions?
Yes, you can.
- term - "a word or group of words having a particular meaning, especially in a specific field"
- "recirculation" and "slow leak" are engineering terms.
- "apoptosis", "mitral regurgitation" and "congestive heart failure" are medical terms.
- "litigation" and "Habeas Corpus" are legal terms.
- "metalanguage" and "leading question" are linguistic terms.