Random rhyme is not a standard technical term in poetry, but it is sometimes used informally to describe occasional rhymes that appear without a regular pattern or planned rhyme scheme. The rhymes may sound accidental or loosely connected, rather than part of a structured pattern such as end rhyme, couplets, or a fixed form.
Because the phrase is vague, a more precise term is usually better when discussing a poem's sound pattern.
Example
Night drifts over the garden wall,
A silver spoon beside the rain;
The window hums, the loose boards call,
And somewhere far, a train, a train.