Scientists, and the media, unanimously refer to this as "cigar-shaped," which is the term they use when they want you to think about dongs but are too afraid to just come out and say "dong."
Seriously, that has to be what they're doing, right? Because otherwise, "cigar" is a dumb point of reference. How many of us smoke cigars? When was the last time you even saw a cigar? They could call that shape "finger-like," or "shaped like a log," or just plain "oblong" and we'd get it, but no, they all refer to it as "cigar-shaped" to really drive home that they mean phallic. In particular, scientists note the similarity in shape to the interstellar object from Arthur C. Clarke's Rendezvous With Rama, and it makes sense that that object in that book would be cylindrical, considering how much Arthur C. Clarke spacecraft are made of genitals.
So, 'Oumuamua is called cigar-shaped. But we don't know if it really is. 'Oumuamua is roughly the size of a city block, which is huge for a cigar but tiny on a celestial scale, so there's no way to focus our telescopes on it and examine it. When we said earlier that scientists observed 'Oumuamua, we meant that scientists picked up the radiation that it reflects as it rotates, and they used that to infer its shape. They might have got it wrong. It might instead be a disc, like in this other NASA illustration: