What does ''say'' mean in ''Say, let's put on a show''?

0 01b00(let's) say02b02br
00used to introduce a suggestion or possible example of something:02br
01i00Try and finish the work by, let's say, Friday.02i02br
01i00Say/Let's say02i00 00(= If we accept)00 01i01b00(that)02b00 the journey takes three hours, that means you'll a

0 It's merely an interjection, like Hi, or Hello, but it probably was originally "I say".0-

0 01blockquote

01cite10Feebs1112cite10It's merely an interjection, like Hi, or Hello, but 10it probably was originally "I say".12br
12blockquote

10 01b01font00Or even possibly, "What do you say..."02font02b00 0-

0 01blockquote

02br
10What does 11i10say12i10 mean in 11b11i10''Say, let's put on a show''12i12b10?12br
12blockquote

12br
00 With a 01i00let's02i00 imperative it means something like "I've just had an idea!" if it means much at all. With a question