If you take the first and last letters of each word, you get the abbreviation for a US state. Then for each of the three lines, the states listed spell out a letter if you look at them on a map.

Sad Wally, ugliest Alcatraz impala, mimeo abhorrer, lava continuo, kneels.

South Dakota, Wyoming, Utah, Arizona, Iowa, Missouri, Arkansas, Louisiana, Colorado, Kansas

spells out "A"

Mean nerd met imperiled underservant; cuckoo kisses Ina Nagle.

Minnesota, North Dakota, Montana, Idaho, Utah, Colorado, Kansas, Iowa, Nebraska

spells out "G"

Met nerd, men worry cello neoclassicism negate Icaria tox lava.

Montana, North Dakota, Minnesota, Wyoming, Colorado, New Mexico, Nebraska, Iowa, Texas, Louisiana

spells out "E"

So the answer is:

AGE

If you take the first and last letters of each word, you get the abbreviation for a US state. Then for each of the three lines, the states listed spell out a letter if you look at them on a map.

Sad Wally, ugliest Alcatraz impala, mimeo abhorrer, lava continuo, kneels.

South Dakota, Wyoming, Utah, Arizona, Iowa, Missouri, Arkansas, Louisiana, Colorado, Kansas

spells out "A"

Mean nerd met imperiled underservant; cuckoo kisses Ina Nagle.

Minnesota, North Dakota, Montana, Idaho, Utah, Colorado, Kansas, Iowa, Nebraska

spells out "G"

Met nerd, men worry cello neoclassicism negate Icaria tox lava.

Montana, North Dakota, Minnesota, Wyoming, Colorado, New Mexico, Nebraska, Iowa, Texas, Louisiana

spells out "E"

So the answer is:

AGE

If you take the first and last letters of each word, you get the abbreviation for a US state. Then for each of the three lines, the states listed spell out a letter if you look at them on a map.

Sad Wally, ugliest Alcatraz impala, mimeo abhorrer, lava continuo, kneels.

South Dakota, Wyoming, Utah, Arizona, Iowa, Missouri, Louisiana, Colorado, Kansas

spells out "A"

Mean nerd met imperiled underservant; cuckoo kisses Ina Nagle.

Minnesota, North Dakota, Montana, Idaho, Utah, Colorado, Kansas, Iowa, Nebraska

spells out "G"

Met nerd, men worry cello neoclassicism negate Icaria tox lava.

Montana, North Dakota, Minnesota, Wyoming, Colorado, New Mexico, Nebraska, Iowa, Texas, Louisiana

spells out "E"

So the answer is:

AGE

If you take the first and last letters of each word, you get the abbreviation for a US state. Then for each of the three lines, the states listed spell out a letter if you look at them on a map.

Sad Wally, ugliest Alcatraz impala, mimeo abhorrer, lava continuo, kneels.

South Dakota, Wyoming, Utah, Arizona, Iowa, Missouri, Arkansas, Louisiana, Colorado, Kansas

spells out "A"

Mean nerd met imperiled underservant; cuckoo kisses Ina Nagle.

Minnesota, North Dakota, Montana, Idaho, Utah, Colorado, Kansas, Iowa, Nebraska

spells out "G"

Met nerd, men worry cello neoclassicism negate Icaria tox lava.

Montana, North Dakota, Minnesota, Wyoming, Colorado, New Mexico, Nebraska, Iowa, Texas, Louisiana

spells out "E"

So the answer is:

AGE