The crossword solution for the term PLAYFULLY TRICKY is ARCH, which is a four-letter word. An ARCH is a curved structure that is used to span an opening and support the weight above it. It is commonly used in architecture and engineering, and can be found in many structures such as bridges, doorways, and windows. The term 'playfully tricky' could refer to the fact that arches are often used to create interesting designs and shapes, making them both playful and tricky to construct.