spiky

From spike (“kind of inflorescence in which sessile flowers are arranged on an unbranched elongated axis”) +‎ -y (suffix forming adjectives with the sense “having the quality of”). Spike is derived from Middle English spik, spike (“ear of grain; clove of garlic; plant having spikes; plant of the genus Valeriana, especially Valeriana officinalis; plant of the genus Lavandula, lavender”), from Latin spīca (“ear, head, or spike of grain; plant spike”) (feminine) (also rarely spīcum (neuter) and spīcus (masculine)), possibly ultimately from Proto-Indo-European *spey- (“long; sharp; thin”).