[ex.pa.ti.ate] vi -at.ed ; -at.ing [L exspatiatus, pp. of exspatiari to wander, digress, fr. ex- + spatium space, course] (1538) 1: to move about freely or at will: wander
2: to speak or write at length or in detail "expatiating upon the value of the fabric --Thomas Hardy" -- ex.pa.ti.a.tion n