verb (used without object), en·thused, en·thus·ing.
- to be or become enthusiastic; show enthusiasm: All the neighbors enthused over the new baby.
verb (used with object), en·thused, en·thus·ing.
- to cause to become enthusiastic.
- to feel or show or cause to feel or show enthusiasm
v.1827, American English, back-formation from enthusiasm. Originally often humorous or with affected ignorance. Related: enthused; enthusing.