Eccentricity refers to the shape of the orbit, derivable from the highest and lowest distances in the orbit of the orbiting body (there's actually a bunch of ways to calculate it that are mathematically equivalent). It's related to modeling orbits as conic sections. An eccentricity of 0 is a perfect circle, <1 is a normal elliptical orbit, >=1 is an escaping trajectory.
For example, Earth's orbit around the sun is ~0.0167, Pluto's is 0.248.
We don't have enough data of the object yet to say basically anything at all about its shape.
We have numbers with a wide error bar.
For ‘Oumuamua in 2017, some method was used to determine its shape, which is (apparently) remarkably elongated. Is it possible to determine the elongation of the new object?
https://science.nasa.gov/solar-system/comets/oumuamua/