hEnglishOxford New American Dictionaryh /āCH, eɪtʃ / ▸ abbreviation 1 (in measuring the height of horses) hand(s): pinto pony gelding—quiet, 13.3 h, great with kids. 2 [in combination] (in units of measurement) hecto-: wine production reached 624,000 hl last year. 3 horse. 4 (especially with reference to water) hot: nine rooms, all with h & c. 5 hour(s): breakfast at 0700 h. ▸ symbol Physics Planck's constant.