large
紘 centers on largeness, especially in the sense of a broad, overarching connection or a thick, sturdy rope that binds things together on a grand scale.
紘 combines 糸 (thread) with 厷, which likely contributes the sound and the idea of something broad or overarching. The character originally referred to a large rope or cord used to tie ceremonial headwear, symbolizing a grand connection.
The thread radical 糸 on the left and the broad shape 厷 on the right suggest a thick, expansive rope. Imagine a giant ceremonial cord that stretches across a vast hall, symbolizing largeness.
For コウ, picture a colossal rope coiling around a huge pillar: the co- in coiling cues コウ, and the rope's immense size reinforces the meaning of large.