Material (evidence or information)

[Cobuild: 7. ADJ : ADJ n]

Material evidence or information is directly relevant and important in a legal or academic argument.[FORMAL]

• The nature and availability of material evidence was not to be discussed.
  

[AmH: 4] Being both relevant and consequential; crucial:

• testimony material to the inquiry.
  

[WorNet 3.0: Adj.3]

directly relevant to a matter especially a law case;

• "his support made a material difference";
• "evidence material to the issue at hand";
• "facts likely to influence the judgment are called material facts";
• "a material witness"
• (Ant) immaterial: of no importance or relevance especially to a law case; "an objection that is immaterial after the fact"

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cf. Synonyms: relevant, pertinent, germane, material, apposite, apropos

These adjectives describe what relates to and has a direct bearing on the matter at hand.

• Something relevant is connected with a subject or issue: performed experiments relevant to her research.
• Pertinent suggests a logical, precise relevance: assigned pertinent articles for the class to read.
• Germane implies close kinship and appropriateness: "He asks questions that are germane and central to the issue" Marlin Fitzwater.
• Something material is not only relevant but also crucial to a matter: reiterated the material facts of the lawsuit.
• Apposite implies a striking appropriateness and pertinence: used apposite verbal images in the paper.
• Something apropos is both to the point and opportune: an apropos comment that concisely answered my question.