stem    umutūmba
(of word) itsina
En-En dictionary 
kuzūnguruka (-zūngurutse)   v    to go around, to cycle (the stem 'zungu' is also the origin of umuzungu, which does not mean 'white person' but rather 'someone going around', describing the first European explorers)
itsina (ama-)     5  class 5
singular: i-,iri-
plural: ama-
(gram.) root or stem of word
word    ijāmbo, amajāmbo, amagambo
(root or stem) itsina
(one who speaks with senseless repititions of ~) ikirogorogo
(to not keep one's ~, or to do that which you declared you wouldn't) kwīrahuruza
En-En dictionary 
umutūmba (imi-)     2  class 2
singular: umu-
plural: imi-
1. stem, trunk of tree, 2. torso of person or animal
digestive system   ibihimba vy'ihokwa
(-ka), inzira y'ibiribwa, ibihimba vy'umubiri vyo guhokwa
En-En dictionary 
 stem found in: Kirundi I (Study lessons)
lesson 15   Special Uses of Class 4 iki–, ibi–
lesson 16   –ra Present Tense of Verb
lesson 22   Infinitive and Imperative
lesson 31   Negative of Future
lesson 41   –ose (All, Every)
lesson 42   “To wash”
lesson 51   Ordinary Past Tense I
lesson 52   Rules for Past Endings
lesson 53   Past Verb Endings
lesson 57   Object Pronouns I
lesson 66   Imperatives with the Subjunctive
lesson 78   Causative Verbs I
lesson 103   Reflexive Verbs
lesson 111   How to Say “Some”; The Conditional
lesson 113   Reduplicated Verbs
lesson 124   Narrative Tenses II
 stem found in: Kirundi II (Grammar)
chapter 7   “never-yet” Tenses
chapter 11   Subjunctive and Imperative
chapter 15   –ribu– Tenses
chapter 16   Prefixless Past Tense
chapter 19   Strong Negative Imperatives
chapter 21   Intensive Form: Infix –na–
chapter 22   Participles
chapter 29   Opposites
chapter 51   Nouns made from Verbs