Donna J.,
Meter is a complicated subject. Having majored in English and taught English, I'll try to explain in a nutshell. Any decent college-level literature text should give examples.
When you're talking about meter, you're talking about an organized way of describing the rhythm of a word, phrase, sentence or poem. In traditionally structured poetry, lines are often organized into repetitive metrical patterns. Each line is a repetition of the pattern. Each equal section is called a foot. The foot is made up of stressed and unstressed syllables. When you scan a poem, or figure out its meter, you use little acute accents and little sideways parenthesis to indicate the stressed and unstressed syllables. (i'm sure there's a name but I don't know what it is).
Since you're musical you might almost think of a foot as a measure and the line of poetry as a line of of a hymn, perhaps.
Anyway, there are different kinds of feet, each of which has a distinct pattern of stressed and unstressed syllables.
Here are the basic ones with some examples of the rhythm:
IAMB Michelle (unstressed, stressed)
TROCHEE Verla (stressed, unstressed)
ANAPEST can't think of an example--two unstressed followed by a stressed
DACTYL Stephanie (stressed, unstressed, unstressed)
SPONDEE John Brown (two stressed)
Then you count the number of feet in each line. The terms to describe the number are monometer, dimeter, trimeter, tetrameter, pentameter, hexameter, heptameter, and so on.
Thus you have terms like iambic pentameter, which means a line of five iambs) or dactyllic tetrameter, a line of four dactyls.
Shakespeare's sonnets and many of the lines from the plays are written in iambic pentameter. This is the commonest English meter.
"Shall I compare thee to a summer's day?"
Dr. Seuss often wrote in anapestic tetrameter. In this example, the feet are anapests (u, u, s) and there are four:
"So I sat there with Sally. We sat there, we two."
Sometimes substitutions of meter are made in verse to add interest or effect, or to make it less sing-songy, but it has to be done well. As I said, Shakespearean sonnets are in iambic pentameter, but take a look at this:
"When in despair with fortune, and men's eyes,
I all alone beweep my outcast state . . ."
The first line is not really iambic pentameter because it ends with a spondee, and "outcast state" has to be read with all stressed syllables or it can't be pronounced properly. But it works -- the emphasis on "outcast" calls attention to it, strengthening the image of the despondency and loneliness of the speaker.
Prosody is a complicated subject and I'm no expert, but I hope this gives you an idea of what your critiquer was refering to. If you find it interesting, there's much, much more to know. Hope it helps.
Anne Marie