From about 1.5 to 2 on this timescale, there's a lot of periodicity (the vertical stripes), and a strong first formant (the dark bar at the bottom), but not much energy above that. We don't see any other especially strong formants, for example, or any energy up at high frequencies. This usually indicates a sonorant consonant, such as
From 2 to 7 or so, we see that same periodicity, but now with multiple strong formants. This generally indicates a vowel or semivowel, like
/j/. Furthermore, those formants change significantly over the course of the vowel, which suggests a diphthong.
The start of the diphthong has a very high second formant, up around 2500 Hz, which tends to indicate a front vowel. High vowels tend to be more fronted than low vowels, so I'm guessing this is an
/i/ or a
The end of the diphthong has a second formant somewhere around 1250 Hz, which isn't especially front or especially back, so I'm guessing that's a schwa (
Finally, from 7 onward, we see a lot of noise, which tends to indicate a fricative. There's a lot of it at very high frequencies, which usually means a sibilant. And at the same time there's still periodicity (the regular vertical bars at the bottom), which indicates that it's voiced.
Putting it all together, I'm guessing that this is a word like "nears" in a non-rhotic accent (/niəz/). The next step would be to record myself saying "nears" and comparing the spectrogram of my recording against the given one, seeing which parts look similar and which parts look different. Personally I've never been good at distinguishing sonorants, so I'd probably also try "leers" and "rears", and see which one looks closest.
(P.S. This recording doesn't seem to have any stops in it, but you can identify those by a period of almost total silence followed by a distinct release.)