| sine wave | |
| —n | |
| any oscillation, such as a sound wave or alternating current, whose waveform is that of a sine curve | |
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| a chattering or flighty, light-headed person. |