A big crossword development exists, for Gerbil has indeed journeyed knowingly long, may now openly present, quickly, really strange tales under very weird xeric young zips...
$1$ is simply the indefinite article
While $2$ is existing, such as any particle
$3$ can be worn, it’s a type of hat
$4$ is an entrance, such as that to a flat
Now $5$ is next, it is to go in
$6$ means weak, such as being hit on the shin
$7$ is moan and 7 is whine
$8$ is funny, 8 is good times
$9$ isn’t real, its all a dupe
$10$ is a writer who looks for scoops
Unit of pressure to $11$ is tied
$12$’s running lengthwise, from side to side
$13$ of many cells is made
Under 100 nm is $14$, a tech upgrade
$15$ is emotional, but over the top
$16$ are fossil scientists, the ground is their shop
$17$ is 10 to the power of one-five-three
$18$ is a measure of reflectiveness on a sample, and to what degree
$19$ is great concentration on a particular skill
$20$’s relating to rock formations after a tectonic thrill
And lastly $21$ is belonging to 10 to the power of one-five-six
You’re not finished yet, up my sleeve are some tricksSpot the patterns in the crossword you see
And tell me, what would the answer to $22$ be?