Rashi on Genesis 41:19/רש"י על בראשית מ״א:י״ט

1דלות means LEAN, as (2 Samuel 13:4) “Why art thou thus becoming (דל) lean?” which occurs in the narrative of Amnon.

2ורקות בשר AND LEAN-FLESHED — wherever רקות is found in Scripture it means spare (literally, deficient) of flesh; old French flouet.