琵(pí) - bound character in pipa, the Chinese lute in Mandarin

琵 (pí) is not a word you can use on its own. It exists in modern Mandarin only as the first half of 琵琶 (pí pá), the four-stringed pear-shaped lute that is one of the oldest and best known Chinese instruments.

The pairing is worth knowing because 琵琶 turns up far more often than a learner expects: in music, in poetry, in the title of the Tang poem 琵琶行, and on any programme of traditional Chinese performance. The measure word for the instrument is 把, the same one used for anything with a handle.

The trap is assuming a single character always equals a word. Plenty of common characters, this one included, are bound morphemes that only ever appear inside a fixed compound. Learn 琵 as half of 琵琶 and never try to use it alone. Watch the tone too: 琵 is second tone pí, which sounds identical to 皮 (skin) and 疲 (tired), so context does all the work.