Is it an Ordered Word?
Python 2, 164 148 132 77 bytes

-16 bytes thanks to Rod's suggestion elsewhere. A frickin' -55 bytes thanks to Arnold Palmer.



n=[min(int((ord(i)-58)/3.13),9)for i in input()]
print sorted(n)in[n,n[::-1]]


Try it online!

Input must be uppercase. Outputs True or False based on its orderedness.



Explanation

The first line maps each letter to a number.

                               for i in input()   # iterate over the input string
            ord(i)                                # take the ASCII ordinal
                  -58                             # subtract 58
           (         )/3.13                       # divide by 3.13
       int(                )                      # chop off the fractional part
   min(                     ,9)                   # choose the minimum between the number and 9
n=[                                            ]  # assign the resulting list to n


This works based on:

          | 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
----------+------------+------------+------------+------------+------------+----------------+------------+-----------------
ord(x)    | 65  66  67 | 68  69  70 | 71  72  73 | 74  75  76 | 77  78  79 | 80  81  82  83 | 84  85  86 | 87  88  89  90
----------+------------+------------+------------+------------+------------+----------------+------------+-----------------
x - 58    | 7   8   9  | 10  11  12 | 13  14  15 | 16  17  18 | 19  20  21 | 22  23  24  25 | 26  27  28 | 29  30  31  32
----------+------------+------------+------------+------------+------------+----------------+------------+-----------------
x ÷ 3.13* | 2.2 2.6 2.9| 3.2 3.5 3.8| 4.2 4.5 4.8| 5.1 5.4 5.8| 6.1 6.4 6.7| 7.0 7.3 7.7 7.9| 8.3 8.6 8.9| 9.3 9.6 9.9 10.2
----------+------------+------------+------------+------------+------------+----------------+------------+-----------------
int(x)    | 2   2   2  | 3   3   3  | 4   4   4  | 5   5   5  | 6   6   6  | 7   7   7   7  | 8   8   8  | 9   9   9   10
----------+------------+------------+------------+------------+------------+----------------+------------+-----------------
min(x, 9) | 2   2   2  | 3   3   3  | 4   4   4  | 5   5   5  | 6   6   6  | 7   7   7   7  | 8   8   8  | 9   9   9   9


*Values are rounded. :P

The second line outputs if the list of numbers is in ascending or descending order.

print                                             # print whether...
      sorted(n)                                   # n sorted...
               in[n,n[::-1]]                      # is equivalent to n or n reversed