UBS Dictionary of the Greek New Testament

Sense 1: cubit, eighteen inches, half meter

Semantic entry: 81.25

Semantic domains: Spacial Dimensions

Subdomains: Specific Measures of Length

Definition: traditionally the distance from the elbow to the end of the fingers, about eighteen inches or one-half meter

Notes: The interpretation of πῆχυς in RV MAT 6:27 · LV MAT 6:27 · Read together MAT 6:27 as a measurement of stature rather than length of life may be justified as an instance of literary hyperbole or exaggeration. Most modern translations, however, interpret πῆχυς in this context as a reference to length of life rather than as a measurement of height (see discussion under ἡλικία[a] in 67.151: ἡλικία).

Further resources: realia:11.4.2.1