Assuming that the first letter is the article, let us center this word: PS-t.
The basic is the quite known verb מָצָא, find or, if you prefer, the stem מצ"א, find.
We find in the dictionary the noun מִמְצָא, a finding. Its plural is מִמְצָאִים, findings.
As regards the singular look at ptr P-t325.2
And as regards the plural, namely our word, look at ptr PS-t1127.