Spike

hřeb

(very large nail)

jelínek

(zoology: an adolescent male deer)

klas

(ear of grain — see also ear)

klas

(botany: kind of inflorescence)

prudké zvýšení

(sharp peak in a graph)

prudký nárůst

(sharp peak in a graph)

smeč

(volleyball)

tretry

(informal: running shoes with spikes in the soles)