making dropdown list wider without making cell wider ???

Sorry, I was offline for a few days.

Try this variation:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim defaultWidth As Double
defaultWidth = 5
    If Target.Count > 1 Then Exit Sub
    Select Case Target.Column
    Case 5, 9, 13, 17, 21, 25
        Target.Columns.ColumnWidth = 20
    Case Else
        Range("5:25").ColumnWidth = 1.43
    End Select
End Sub

When you select a cell in any column other than 5, 9, 13, 17, 21, and 25, these columns will revert back to the narrow size.