一技之长
yī jì zhī cháng · HSK 7
proficiency in a particular field
🛠️ 一技之长 = 一 one + 技 skill + 之 's + 长 forte: one skill that is your strong point
长 here means strong point or forte (not length), read cháng. The idiom names having one specialized skill you excel at. Contrast with 长 read zhǎng meaning to grow or elder.
一 — single horizontal stroke
一 is one of the simplest pictographs in Chinese, depicting a single horizontal line to represent the number one. It has retained essentially the same form since oracle bone script over 3,000 years ago. By extension it also means 'first,' 'whole,' or 'same.'
之 — foot 止 above ground line 一
Originally a pictograph of a foot (止) stepping forward from a baseline, meaning 'to go' or 'to proceed'. Over time the concrete 'going' sense faded, and 之 was borrowed as a grammatical particle marking possession ('of') or as a pronoun ('it'), which became its dominant use in Classical Chinese.
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.