What it means
گچ (gach) is a native Persian word that goes back to Middle Persian gač and refers to gypsum or plaster as a material. From that base meaning the word branched in two everyday directions: in a medical context it means the plaster cast applied to a broken bone, and in other contexts it means chalk (the kind used on a blackboard) or plaster used in construction. When a doctor says “pât-at ro gach migirim” he means “we are putting your leg in a cast.” The two uses are always clear from context, and there is no confusion between them in daily speech.
How to use it
- دستم گچ گرفته. (dastam gach gerafte.) “My arm has been put in a cast.”
- گچش رو کِی باید بکنه؟ (gachash-o key bâyad bokone?) “When does he need to have the cast taken off?”
- با گچ رو تخته نوشت. (bâ gach ru-ye takhte nevesht.) “She wrote on the board with chalk.”
- پام تو گچه. (pâm tu-ye gach-e.) “My leg is in a cast.”
Cultural note
Gypsum (gach) has been quarried and used in construction across the Iranian plateau for thousands of years, and elaborate gach-kari (گچکاری, plasterwork) decorates the interiors of historic mosques and mansions such as those in Isfahan and Yazd. The same word in its medical sense is entirely modern clinical usage adopted when plaster casting became standard orthopaedic practice. A broken arm or leg in a cast is immediately recognized by the Persian phrase “gach dare” (he has a cast on).