Diminished chords! They’re bluesy, jazzy, uptown!  There’s really only one shape to learn, which can move anywhere on the fretboard. REALLY!   AND each note in that shape is the name of a diminished chord. Yowser.  AND  you can move up 3 frets on the fretboard and you have the same chord, just squeakier.  AND they are really “Diminished 7th chords” but we don’t need to know that.  AND they can look like this on the song charts: Cdim, or C-, or C°, or Cdim7.  Gee.
These chords have attitude.

These 2 pages are to show you the relationship of the diminished chord shape to the notes in it. The first one is the list that Uke Mike had on his video that I sent this weekend. Dim. Chord list, Uke Mike The other one shows you all the fretboard notes.  It’s from the back of the Ukulele Chord Dictionary, if you have that book, you don’t really need this pageFretboard notes (Uke Chrd Dict)
Download these:  When The Red Red Robin Comes Bob Bob Bobbing Along    ,Up-A-Lazy-River-2-16-20,    I Fall To Pieces   Along Came Jones