Penno Family History

O. J. Padel suggests it may be a hypocoristic form (with the Cornish suffix -ow) of a name in Pen- such as Pentec ‘fair head’ (Cornish pen ‘head’ + tec ‘fine fair’) attested in Roger Richard and William Pentec about 1230-5 in Cornish Deeds (Pydar Hundred) or Pengwyn ‘white head’ (Cornish pen + gwyn) attested in John Pengwyn 1514 in Cornish Deeds (Saint Columb Major Pydar Hundred Cornwall).

Apart from the Saltash example below all the earliest bearers of Penno(w) etc. are located in places in Pydar Hundred. Alternatively, perhaps a variant of Penn (3) a pet form of the Middle English female personal name Pernel (see Parnell) + the Cornish hypocoristic suffix -ow.

Since Parnell is an especially common surname in Devon and Cornwall it is reasonable to suppose that Pernel was used as a given name there.