[いっそう, issou] (adv, adj-no) (1) (uk) much more; still more; all the more; more than ever; (n, adj-no) (2) single layer (or storey, etc.); (adv) (3) (arch) (See いっそ) rather; sooner; preferably; (P)#14746
[いちだん, ichidan] (adv-to, adv) (1) more; much more; still more; all the more; (n) (2) step; rung; level; rank; (3) paragraph; passage; (4) (e.g. 食べる) (See 五段・1) Japanese verb group; (5) first rank (in martial arts, etc.); (P)