Refers to the ocean tide. Often used in compound terms like タイドプール (tide pool) or タイドグラフ (tide graph).
I found a small crab in the tide pool.
tied (e.g. tied aid)
Used in economic or political contexts to describe aid or conditions that are linked to specific requirements. Often appears in the phrase タイド援助 (tied aid).
Tied aid often requires purchasing goods from the donor country.