Concise Bible Dictionary:
Used typically for the source of nourishment. Israel “shall suck the breast of kings” (Isa. 60:16; compare Isa. 49:23; see also Job 24:9; Isa. 66:11).
Strong’s Dictionary of Greek Words:
Meaning:
from 2476 (as standing prominently); the (entire external) bosom, i.e. chest