2. Adjective. Pertaining to empty gesturing, with little substance behind it; vague. ¹
3. Noun. (context: chiefly figuratively) Frantic or conspicuous gesturing (during an argument etc.), especially as contrasted with a lack of underlying substance or meaning; empty gesturing. ¹
4. Verb. (third-person singular of handwave) ¹
¹ Source: wiktionary.com