rice field ridge path
畷 centers on a narrow raised path between rice fields, a ridge path used for walking along the edges of paddies.
畷 combines 田 (rice field) with 叕, which likely contributes the sound and may relate to connecting or linking, suggesting a path that connects fields.
The left side 田 is a rice field, and the right side 叕 looks like a series of connected lines. Picture a narrow raised path weaving between flooded paddies, linking them together.
For テツ, imagine walking along the ridge path in a pair of iron (鉄, てつ) geta that clank with each step: 鉄 -> テツ, and the path keeps you above the muddy field.
Shijonawate Gakuen University