Boulder and Jacks

Boulder noun - A large smooth mass of rock detached from its place of origin.

Jacks and boulder are semantically related. In some cases you can replace term "Jacks" with "Boulder", this nouns are similar.

Jacks noun - A game in which jackstones are thrown and picked up in various groups between bounces of a small rubber ball.

Boulder and jacks are semantically related. Sometimes you can use "Boulder" instead a noun "Jacks".