专长
zhuāncháng · HSK 7
knowledge
🎯 专长 = 专 specialized + 长 strong-point: your specialty or forte
专 means focused or specialized; 长 here is the forte sense of the character (a strong point), not length. Together they name the one skill someone is expert at.
长 — pictograph of long-haired person with cane
Originally a pictograph showing a person with long, flowing hair leaning on a cane, representing an elder. The meaning extended from 'long hair' to 'long' in general, and also to 'elder' or 'to grow' (read zhǎng). The modern form 长 is a simplification of the traditional 長.