noun · a localized, painful swelling or inflammation on the skin, such as a sore or pustule

他腿上长了一个红肿的脓瘩，疼得厉害。

noun · the hard, protective crust that forms over a wound while it is healing

伤口已经结了硬瘩，千万不要用手去抠。

used in 疙瘩 gē​da, meaning a lump or pimple

他腿上长了一个小疙瘩。