Reibun
、。

Nordic combined is a winter ski sport — a competitive event that combines two Nordic ski disciplines, cross-country skiing and ski jumping.

Literal

Nordic-combined [topic-は] winter ski competition-sport [gen-の] one [copula-で], cross-country-ski [and-と] ski-jump [called-という] two [gen-の] Nordic-ski competitions [obj-を] combine-[and-て] compete competition [gen-の] thing [copula-である].

A classic encyclopedia-style definition sentence. Notable features: (1) ~のことである is the definitional copula ('it is the matter of / refers to X'), the most formal variant of the dictionary-entry ender; (2) multiple sinitic compounds stacked (冬季, 競技, 組み合わせる); (3) two identity clauses joined by the mid-sentence で (the conjunctive form of だ/である).