  In this note we focus on the defect of singular plane curve that was recently
introduced by Dimca. Roughly speaking, the defect of a reduced plane curve
measures the discrepancy from the property of being a free curve. We find some
lower-bound on the defect for certain classes of irreducible plane curves
admitting nodes, ordinary cusps and ordinary triple points. The main result of
the note tells us that reduced simply singular plane curves with sufficiently
high Arnold exponents are never free.
