köken: Borrowed from Latin plēnus, whence also Spanish lleno, which is an inherited doublet.
aile: a plena luz del día, a pleno pulmón, de pleno, de pleno derecho, dedicación plena, en pleno, plenamente, pleno empleo, pleno invierno, pleno verano
Internationalism; possibly borrowed from German Plenum, French plenum, or English plenum, ultimately from Latin plēnum. First attested in the 20th century. Doublet of ful and pełny.