A short fixed showpiece that drives to a threefold cadence — compact, composed, emphatic.
A short fixed composition — a few matras to a couple of avartans — that states an idea and drives directly into a closing tihai. Where a kaida develops, a tukra strikes: it is the repertoire's short-form cadence piece, equally at home in solos, Kathak, and accompaniment gaps.
Tukras often mix open paran-type language with crisp closed text for contrast. Every player carries a stock of them in the common talas; part of the craft is entering one so its tihai lands regardless of where in the cycle you began.
Further reading
Sudhir Kumar Saxena, The Art of Tabla Rhythm: Essentials, Tradition and Creativity (Sangeet Natak Akademi / D.K. Printworld, 2006).