TDNT (1964): kephale means 'first, supreme, prominent, outstanding, determinative'; acknowledges source for rivers but includes subjection

The TDNT (1964) says kephale refers to 'not merely what is first or supreme... but also what is prominent, outstanding, or determinative. Man's head is not just one member among others; it is the first and chief member which determines all the others.' Source is acknowledged in relation to rivers, but 'subjection to the head is strongly included in its meaning' for other uses. Mike notes the river usage may actually mean 'extremity' (kephale in plural = sources, singular = mouth of river).