culm 1
/kulm/ , n.
1. coal dust; slack.
2. anthracite, esp. of inferior grade.
[ 1300-50; ME colme, prob. equiv. to col COAL + -m suffix of uncert. meaning (cf. -m in OE faethm fathom, waestm growth) ]
culm 2
/kulm/ , n.
1. a stem or stalk, esp. the jointed and usually hollow stem of grasses.
v.i.
2. to grow or develop into a culm.
[ 1650-60; culmus stalk; akin to CALAMUS, HAULM ]