三十八

Two-character 三八 sānbā has a famous double life: it's the date of International Women's Day (三八节, March 8) yet in Taiwanese / southern slang it's an insult for a flighty woman. The full three-character 三十八 simply means '38' and avoids the slang reading.

三八式 sānbā shì also refers to the Japanese Type 38 Arisaka rifle, ubiquitous in Chinese WWII films - 三八大盖 is the standard nickname.