[bonanova]

OK, we're going to the next level.

Seven-letter words, no plurals, repeated letters or proper names.

Except:

1. The Z-word is plural.
   
2. The D-word, the K-word and the M-word each have one repeated letter.
   For one of them, the repeated letter is the initial letter.
   

To get you started, the X-word is listed in the spoiler.

It is obscure, the only one I could find that fits the letter pattern for this puzzle.

Read about the letter pattern in the spoiler.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ']A - ANGELIC - hookemhorns

B - BOULDER - Inzuri

C - CAPSULE - Cherry Lane

D * DAQUIRI - Cherry Lane

E - ERGODIC - hookemhorns

F - FUCHSIA - Cherry Lane

G - GRATIFY - Inzuri

H - HUSBAND - Pickett

I - INVADER - CaptainEd

J - JAWBONE - CaptainEd

K * KICKBOX - CaptainEd

L - LYNCHED - Inzuri

M * MUZZLED - Cherry Lane

N - NAIVETY - hookemhorns

O - OBSCURE - Pickett

P - PUCKISH - Cherry Lane

Q - QUADRIC - Cherry Lane

R - RECTIFY - Pickett

S - SURFACE - hookemhorns

T - TAGLINE - hookemhorns

U - UNHEARD - CaptainEd

V - VIBRATO - Inzuri

W - WINDJET - Pickett [proper noun it turns out ... oops]

X - XEWKIJA - Free word.

Y - YELPING - Pickett

Z * ZOMBIES - Inzuri

----------------

* The D, K and M words have a repeated letter, and the Z-word is plural

Spoiler for The clue. aka The pattern:

One letter in each word follows a particular pattern with respect to the initial letter.

. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A . 2 4 2 4 3 3 2 4 3 2 4 2 4 2 2 3 3 3 6 3 2 3 3 5 2

B 2 . 3 3 4 1 1 3 3 3 2 3 4 1 5 1 3 2 3 2 4 3 2 1 2 3

C 4 3 . 2 2 4 1 3 2 2 1 3 3 2 4 4 3 2 5 3 3 1 1 2 3 2

D 2 3 2 . 3 3 3 3 4 1 1 1 2 2 2 2 6 2 3 2 4 3 2 2 1 1

E 4 4 2 3 . 2 3 1 4 2 3 3 2 2 4 2 4 4 3 3 3 3 3 2 3 3

F 3 1 4 3 2 . 3 4 2 1 2 2 1 2 3 5 4 3 5 2 3 2 1 2 1 2

G 3 1 1 3 3 3 . 1 3 1 1 1 0 4 1 1 3 5 3 4 2 4 2 2 3 1

H 2 3 3 3 1 4 1 . 3 3 1 3 2 2 3 3 3 0 3 2 5 2 2 1 1 2

I 4 3 2 4 4 2 3 3 . 3 1 3 2 5 2 1 4 3 3 4 5 4 4 3 3 2

J 3 3 2 1 2 1 1 3 3 . 2 2 1 3 3 0 1 1 2 3 3 3 4 4 2 3

K 2 2 1 1 3 2 1 1 1 2 . 1 0 1 3 3 2 2 1 1 0 3 1 3 1 3

L 4 3 3 1 3 2 1 3 3 2 1 . 3 3 2 2 2 3 2 3 4 0 3 1 4 1

M 2 4 3 2 2 1 0 2 2 1 0 3 . 1 2 1 2 1 2 2 3 0 2 1 2 3

N 4 1 2 2 2 2 4 2 5 3 1 3 1 . 1 1 2 4 2 5 3 4 4 3 4 2

O 2 5 4 2 4 3 1 3 2 3 3 2 2 1 . 3 3 3 5 1 3 3 1 1 1 4

P 2 1 4 2 2 5 1 3 1 0 3 2 1 1 3 . 3 2 3 1 2 1 1 2 2 2

Q 3 3 3 6 4 4 3 3 4 1 2 2 2 2 3 3 . 3 4 2 4 3 2 2 1 1

R 3 2 2 2 4 3 5 0 3 1 2 3 1 4 3 2 3 . 4 3 2 3 3 2 3 2

S 3 3 5 3 3 5 3 3 3 2 1 2 2 2 5 3 4 4 . 2 4 2 1 2 1 2

T 6 2 3 2 3 2 4 2 4 3 1 3 2 5 1 1 2 3 2 . 3 3 4 3 5 2

U 3 4 3 4 3 3 2 5 5 3 0 4 3 3 3 2 4 2 4 3 . 2 3 2 2 1

V 2 3 1 3 3 2 4 2 4 3 3 0 0 4 3 1 3 3 2 3 2 . 2 2 1 3

W 3 2 1 2 3 1 2 2 4 4 1 3 2 4 1 1 2 3 1 4 3 2 . 4 3 2

X 3 1 2 2 2 2 2 1 3 4 3 1 1 3 1 2 2 2 2 3 2 2 4 . 2 2

Y 5 2 3 1 3 1 3 1 3 2 1 4 2 4 1 2 1 3 1 5 2 1 3 2 . 2

Z 2 3 2 1 3 2 1 2 2 3 3 1 3 2 4 2 1 2 2 2 1 3 2 2 2 .

[Guest]

What is the pattern?

good question, because I still haven't figured that part out...

[CaptainEd]

What is the pattern?

Each word began with one letter and contained the letter 13 away in the alphabet (A-N, B-O, etc.). Beautifully enough, this relationship is reciprocal, as the N word contains an A (also 13 letters away).

What an ingenious and beautiful relationship! Thanks, Bonanova!

Inzuri and CaptainEd both conform to the pattern (not quite the same as "are comfortable with")

[bonanova]

Each word began with one letter and contained the letter 13 away in the alphabet (A-N, B-O, etc.). Beautifully enough, this relationship is reciprocal, as the N word contains an A (also 13 letters away).

What an ingenious and beautiful relationship! Thanks, Bonanova!

Inzuri and CaptainEd both conform to the pattern (not quite the same as "are comfortable with")

Correct.

M and Z words exposed it nicely.