这只是一个玩笑。

Just joshing.

Source: Tatoeba

Sentence Composition

=1 这 zhè
  1. (pronoun) this; these
  2. (bound form) this; the (followed by a noun)
  3. (bound form) this; these (followed by a classifier) (in this sense, commonly pr. zhèi, esp. in Beijing)
=1 这 zhèi (coll.) this
2 只是 zhǐshì
  1. merely; only; just; nothing but
  2. simply
  3. but; however
=3 一个 yīge
  1. a; an; one
  2. the whole (afternoon, summer vacation etc)
=3 一个 yīgè
  1. Combination of the numeral 一 (“one”) and the generic classifier 個／个: a; an; one
  2. same
4 玩笑 wánxiào
  1. to joke
  2. joke
  3. jest