A type of Japanese verb. The word literally means "vowel-stem", and this makes sense because the Ichidan verbs all end with -iru or -eru. Ichidan verbs are the smaller category of Japanese verbs -- this is a shame, because they are naturally easier to deal with (if only slightly) than the other major class, the Yodan verbs.

Of course, not all verbs that end in -iru or -eru are actually Ichidan verbs. A Yodan verb ending in -ru can therefore look like an Ichidan verb at first, but it isn't. See Yodan for more information and a list of some Fake Ichidan verbs.

Examples of Ichidan verbs are:

To form the stem of an Ichidan verb, simply remove the ru. To form the seven Bases, add:
  1. nothing
  2. nothing
  3. ru
  4. re
  5. yoo
  6. te
  7. ta