Hebrew: 'ayalah (2 Sam. 22:34; Psalm 18:33, etc.) and 'ayeleth (Psalm 22, title)
the female of the hart or stag
It is referred to as an emblem of activity (Genesis 49:21), gentleness (Prov. 5:19), feminine modesty (Song of Songs 2:7; 3:5), earnest longing (Psalm 42:1), timidity (Psalm 29:9).
In the title of Psalm 22, the word probably refers to some tune bearing that name.