trillar

Trillar is a Spanish verb with agricultural and acoustic senses, used primarily to mean either "to thresh" or "to trill." In its agricultural sense, trillar denotes the traditional process of separating grain from stalks and chaff after harvesting. This activity has been carried out on threshing floors with flails or with animal-drawn implements such as the trillo (a heavy wooden or stone board) and has been mechanized in modern agriculture by threshing machines and combine harvesters. The noun trilla refers to both the act of threshing and, in some regions, the communal events historically tied to harvest work.

In its acoustic and musical sense, trillar describes the production of a rapid, repeated sound or ornament, equivalent to the English "to trill." It is applied to bird song, vocal techniques, and instrumental embellishments that involve quick alternation or vibration of notes. The related noun trino denotes the resulting trill or warble.

Etymologically, trillar traces to Latin roots associated with repeated or vibrating sounds and has maintained both literal and figurative uses in Spanish. As a regular -ar verb, it conjugates in standard patterns (trillo, trillaba, trillará, trillando, trillado). Regional speech may extend the term metaphorically to describe noisy, repetitive action or vigorous beating beyond agricultural or musical contexts.