The Collaborative International Dictionary of English v.0.48:
Plani- \Plan"i-\, Plano- \Plan"o-\ [L. planus. See Plane, a.] Combining forms signifying flat, level, plane; as planifolious, planimetry, plano-concave. [1913 Webster]The Collaborative International Dictionary of English v.0.48:
Plano- \Pla"no-\ See Plani-. [1913 Webster]WordNet (r) 3.0 (2006):
Plano n 1: a city in northeastern Texas (suburb of Dallas)