Entry 2 senses · 2 variants Webster, 1913 Culm /(kŭlm)/ · IPA /ˈkʌlm/ n. n. 01 n. The stalk or stem of grain and grasses (including the bamboo), jointed and usually hollow. 1. The stalk or stem of grain and grasses (including the bamboo), jointed and usually hollow.(Bot.) 02 n. Mineral coal that is not bituminous; anthracite, especially when found in small masses. 1. Mineral coal that is not bituminous; anthracite, especially when found in small masses.(Min.)