Ivysaur

The English name for Ivysaur is nothing more than a portmanteau of ivy and saur.

An ivy is a type of vine plant characterised by climbing up other structures as it grows. And, as with Bulbasaur, the suffix saur is pretty self-explanatory and originates from the Greek word saûros meaning lizard.

We can see where Ivysaur gets its English name from as it develops ivy-like vines that can be used as a whip for defence. Curiously, the weight of the bulb, which has now bloomed, prevents Ivysaur from standing on its hind legs.

The official Pokedex entry for Ivysaur is in Katakana フシギソウ (fushigisō) but can be translated to Hiragana as ふしぎそう.

We originally covered under Bulbasaur's description how the Hiragana ふしぎ (fushigi) translates to strange, wonderful, amazing, curious, and mysterious​. Meanwhile, そう (sō) translates to grass. This is likely in reference to the fact Ivysaur happens to be a Grass type Pokémon.

All in all, the Japanese for Ivysaur appears to be as simple as the English in meaning.