楞 is a bound morpheme (不成词语素) meaning the edge or corner formed where two planes meet on an object. It almost always appears inside compound words like 楞角 (corner, angle). In modern standard Chinese, 楞 is an accepted variant of 棱 (léng); the two are interchangeable in most contexts, though 棱 is more common in formal writing. You cannot use 楞 alone as a full word — it must attach to another morpheme.