What is the term for two lines of rhyming iambic pentameter?

The term for two lines of rhyming iambic pentameter is indeed referred to as a heroic couplet. This specific term denotes a pair of lines that not only rhyme but also adhere to the iambic pentameter meter, commonly found in English poetry, particularly during the Renaissance and especially used by poets such as John Dryden and Alexander Pope.

The heroic couplet's structure allows for a rhythmic and thematic cohesion, often encapsulating a complete thought or idea within the two lines. This contrast with other forms like a quatrain, which consists of four lines, or a tercet, which comprises three lines, emphasizes the distinct nature of the heroic couplet as a concise unit of thought. Additionally, a couplet generally refers to any two consecutive rhyming lines, but it does not necessarily specify that they are in iambic pentameter, which is why the label "heroic couplet" is the precise term for the requested form.