Other forms: lumped, lumps, lumping
To lump is to put things together as if they were the same. Lump them together, lumped in with the rest, lump the costs.
It is nearly always a complaint about being treated as part of a group you do not belong to. Lump it means put up with it. As a noun a lump found in the body should be shown to a doctor, whatever the likely explanation.
1verblumpTo put things together as if they were the same.
“Don't lump all teenagers together; most of them are polite and helpful.”
lump is a grouping.
Middle English lumpe comes from a Germanic root about a shapeless mass. Dutch lomp, a rag, is a relative.
Proto-Germanic
*limpaną — to glide, go, hang loosely
Middle English
lumpe
English, today
lump
From Middle English lumpe, from a gem - base akin to Proto-Germanic limpaną (“to glide, go, hang loosely”). Compare Dutch lomp (“rag”), German Low German Lump (“rag”), German Lumpen (“rag”) and Lump (“ragamuffin”).
Etymology from Wiktionary, CC BY-SA