一手

yīshǒu
  1. a skill
  2. mastery of a trade
  3. by oneself
  4. without outside help

CEDICT

Entry Composition

1 一 yī
  1. one
  2. single
  3. a (article)
  4. as soon as
  5. entire; whole; all; throughout
  6. "one" radical in Chinese characters (Kangxi radical 1)
  7. also pr. yāo for greater clarity when spelling out numbers digit by digit
2 手 shǒu
  1. hand
  2. (formal) to hold
  3. person engaged in certain types of work
  4. person skilled in certain types of work
  5. personal(ly)
  6. convenient
  7. classifier for skill

classifiers: 雙, 隻