“Ranchocado (ranch dressing + avocado) is a portmanteau for “avocado-ranch dressing.” “Avocado ranch dressing: has been cited in print since at least 1993.
 
Vegan Sandwiches Save the Day! (2012), by Tamasin Noyes and Celine Steen, included the recipe “Onion Ring Rachocado.” On August 28, 2013, The Huffington Post published “Avocado Ranch Dressing Recipe”:
 
“The avocado-ranch dressing recipe, or ranchocado as we like to think of it, is created by the creative hands of food blogger How Sweet It Is. We’re not sure how long this recipe has been around, or if this food blogger is even responsible for its origins.”
 
         
Google Books
Frommer’s Comprehensive Travel Guide Las Vegas ‘93-‘94
By Rena Bulkin
New York, NY: Prentice Hall Travel
1993
Pg. 128:
Do opt for Paco’s salad of crisp greens tossed with cheeses, avocado wedges, and very thinly sliced red onions in avocado ranch dressing.
 
30 October 1997, Boston (MA) Globe, “Southwestern food and hospitality lure families to Brookline spot” by Sheryl Julian, Calendar, pg. 6:
... Canyon salad with avocado ranch dressing, ...
 
Google Books
Vegan Sandwiches Save the Day!:
Revolutionary New Takes on Everyone’s Favorite Anytime Meal
By Tamasin Noyes and Celine Steen
Beverly, MA: Fair Winds Press
2012
Pg. 38:
ONION RING RANCHOCADO
Ranch dressing, meet avocado. Avocado, meet ranch. Beer-battered onion rings are joining the party, too. You’re all going to get along famously.
 
Rachael Ray Show
July 4, 2012
Club Burger Sliders with Avocado Ranch Dressing
(...)
Avocado-Ranch Dressing:
1 avocado
1/2 cup sour cream
Juice of 1 lemon
1 clove garlic, grated or finely chopped
2 tablespoons finely chopped chives
2 tablespoons finely chopped fresh dill
2 tablespoons finely chopped flat-leaf parsley
 
How Sweet It Is
Cheesy Double Bean Quesadillas with Homemade Avocado Ranch.
February 11, 2013
(...)
avocado ranch
1 ripe medium avocado
1/3 cup sour cream
1/4 cup mayonnaise
2 tablespoons freshly chopped parsley
2 tablespoons freshly chopped dill
1 garlic clove, minced
1 teaspoon worcestershire sauce
1/2 teaspoon white vinegar
1/2 teaspoon smoked paprika
1/4 teaspoon onion powder
1/4 teaspoon salt
1/4 teaspoon pepper
 
The Huffington Post
Avocado Ranch Dressing Recipe
Posted: 08/28/2013 9:19 am EDT
(...)
The avocado-ranch dressing recipe, or ranchocado as we like to think of it, is created by the creative hands of food blogger How Sweet It Is. We’re not sure how long this recipe has been around, or if this food blogger is even responsible for its origins. All we know is that we’re much happier knowing that it exists. And, we plan to put it on everything.
 
Ranchocado is a simple dressing to make. Follow all the steps to make ranch dressing (or cheat and use store-bought) and blend in avocado. Then proceed to put it on everything. That’s it! Get the avocado ranch dressing recipe here and make a really big batch.