Comm. NT: 6. Vipphandana—“wrong kind of excitement”: Vism-mhṭ says here
Uddhumātakakammaṭṭhānavaṇṇanā
the meaning is, it becomes the sign for interference by (activity of) defilement
Phandati and vipphandati are both given only such meanings as “to throb, stir, twitch” and paripphandati is not in PED. For the sense of wrong (vi-) excitement (phandana) cf. IV.89 and XIV.132 and note. There seems to be an association of meaning between vipphāra, vyāpāra, vipphandana, īhaka, and paripphandana (perhaps also ābhoga) in the general senses of interestedness, activity, concern, interference, intervention, etc.