simxu -sim-si'u- gismu

x1 (set) has members who mutually/reciprocally x2 (event [x1 should be reflexive in 1+ sumti]).

Members of x1 do to each other/one another x2, and in return do x2; x1 (plural set) do the same thing x2 to each other. See also kampu, mintu.

In notes:

kampu
x1 (property - ka) is common/general/universal among members of set x2 (complete set).
mintu
x1 is the same/identical thing as x2 by standard x3; (x1 and x2 interchangeable).
basysi'u
x1 (plurality/set) replace/trade places with one another in circumstance x2.
cajysi'u
s1 (set) mutually exchange/trade/barter commodity c2 for c3 with c4.
cpesi'u
x1 ask each other for/request from each other x2 in manner/form x3
da'arsi'u
s1 fight [each other] over issue d3 (abstract).
djusi'u
x1 (plural) help each other doing x2
jalsimgau
g1 [agent/person] claps together/causes to collide/strikes together s1
jalsi'u
s1 (set) collide with each other.
jonsimgau
g1 [person/agent] join s1 together.
jonsi'u
x1 are joined at/by x2.
kucysimgau
g1 folds/crosses/intertwines s1(set).
mitybe'isi'u
s1 (set) mutually synchronize b2 via transmission means/medium b5
pamsi'u
x1 love each other; x1 are in love
papsimbi'o
x1 make up/peace with each other under condition x2.
pedysi'u
x1 are friends (of each other, distributively)
pensi'u
x1 (set) meet at x2 (location).
selfai
f2 shares f1 with portions f3.
siktysi'u
x1 (plurality) interacts in manner x2
simbasti
x1 trades places with x2 in circumstance x3.
simbi'o
x1 (plural) become mutual in property x2 (ka).
simda'a
x1 fight [each other] over issue x2 (abstract).
simkarbi
x1 compares x2 (set/plurality) in property x3 (ka), determining x4 (du'u/state)
simpapybi'o
x1 make up/peace with each other under condition x2.
simpe'o
x1 are friends [of each other].
simselnu'e
x1=n2 is an agreement/contract/treaty between x2=n1=n3
simsikta
x1 interacts with x2 in manner x3
simtermosygau
x1 rubs x2 together.
smisi'u
The members of x1=simx1 (set) resemble one another in property x2=simx2.
spesi'u
si1 is/are married couple(s) under law/custom/tradition/system/convention sp3.
ta'arsi'u
s1 (set) discuss subject t2 in language t4.
tugysi'u
t1=t2=s1 are unanimous / sharing the same view on t3=s2 (du'u).
xanjaisi'u
s1 hold hands/are hand-in-hand.
sefsi
x1 is/are related to itself/himself/herself/themselves by relation x2
zu'ai (exp!)
shows mutual activity between this place and the first place of the current bridi; members participating in the activity are put into the first place (that e.g. can be formed by connecting sumti with {ce} or {jo'u})
imxu
x1 and x2 do x3 (binary ka) to each other.