試訴 is read as しそ (shiso) and means test case.
しそ
shiso
しこうさくご
trial and error
しあん
tentative plan
ししゃ
test firing
しけんけっか
examination results
しけんじょうけん
test conditions
しけんしせつ
test facility
しさくかんきょう
test environment
しせい
trial manufacture (cultivation, etc.)
しあいほうき
forfeiture of a match
しけんぐんもくひょう
test group objective
しけんこうもくめい
test item name
しけんかんとく
proctoring of an exam