Q: Does the word "back" mean the same thing in "Which horse are you backing in this race?" and "Back this enterprise."?

A: the same meaning

Q: Does the word "seat" mean the same thing in "The seat of a saddle." and "He sat on the arm of the chair rather than the seat, which always annoyed his mother."?

A: the same meaning

Q: Does the word "stop" mean the same thing in "Soon the rain will stop." and "The car stopped."?

A: different meanings

Q: Does the word "element" mean the same thing in "Water is the element of fishes." and "In your element."?

A:
different meanings