Nalu
Nalu is the ship name for Natsu and Lucy from Fairy Tail. It is a portmanteau: built by joining a piece of one name to a piece of the other.
Engine version 1.0 · Breakdown computed from the live checker · Research Desk
Structure
The checker cannot resolve the ending of this name against Natsu and Lucy. That is the right answer rather than a failure: built by joining a piece of one name to a piece of the other.
Why this name is shaped the way it is
Two letters plus two. Four-character blends are the shortest form that still carries anything, and they depend entirely on the audience knowing the pair.
What our own engine would have built
Handed Natsu and Lucy with no knowledge of the fandom, the blender proposes Luctsu, Lutsu, Natcy, Natscy, Lucsu, Lusu. Nalu is not among them. That is the normal result, and it is the clearest illustration of why this site refuses to call any candidate the best one. A community picked Nalu for reasons no software can see.
If you want to run the same check on a name of your own, the draft checker does exactly what produced the breakdown above, and the ship name generator builds candidates from two names you supply.
Other portmanteaus
Questions
What does Nalu mean?
Nalu is the ship name for Natsu and Lucy from Fairy Tail. A ship name is a nickname for a pairing, and shipping means wanting two characters to be together.
Who is Nalu?
Nalu is not a person. It refers to Natsu and Lucy as a pairing, which is how fandom communities talk about two characters together in one word.
How was Nalu formed?
Not by blending the two names. Built by joining a piece of one name to a piece of the other. That is why a name checker cannot trace it back to Natsu and Lucy.