sinonim

/sinonim/

Cases

SingularPluralWhen to use it
nominativesinonimthe synonymsinonimlethe synonymsthe plain dictionary form — the doer of the sentence
genitivesinonimnithe synonym'ssinonimlenithe synonyms'the owner — whose it is
accusativesinonimnithe synonym (as the object)sinonimlenithe synonyms (as the object)a specific, known object — whom or what
dativesinonimgeto the synonymsinonimlegeto the synonymsdirection or recipient — to where, to whom
locativesinonimdeat / in the synonymsinonimledeat / in the synonymswhere it is; also having — mende bar, "I have it"
ablativesinonimdenfrom the synonymsinonimledenfrom the synonymswhere it comes from; also "than" when comparing
When to use each case
nominative
the plain dictionary form — the doer of the sentence
genitive
the owner — whose it is
accusative
a specific, known object — whom or what
dative
direction or recipient — to where, to whom
locative
where it is; also having — mende bar, "I have it"
ablative
where it comes from; also "than" when comparing

The endings are the same ones the pronouns wear — that page explains when each case is used.

With an owner

One ownedSeveral owned
mysinonimimmy synonymsinonimlerimmy synonyms
yoursinonimingyour synonymsinonimleringyour synonyms
his / hersinonimihis / her synonymsinonimlerihis / her synonyms
oursinonimibizour synonymsinonimleribizour synonyms
you all'ssinonimigizyou all's synonymsinonimlerigizyou all's synonyms
theirsinonimleritheir synonymsinonimleritheir synonyms

The overlap in the last rows is real, not a mistake: sinonimleri can mean "his / her synonyms", "their synonym", or "their synonyms" — context decides.