# Between two walls

For each box, the given words can be divided into four groups of four words each, according to some criteria. The names of the resulting categories can in turn be used to find out a final two-word answer.

#1

acid        alkaline    bath        brain
car         eclipse     hail        hound
lithium     money       panel       pressure
sand        snow        system      wind


#2

boat        cameral     half        holy
home        hot         lingual     mineral
monthly     oil         pedal       shelf
sea         still       way         wild


This puzzle is part of Recycling old answers.

• Are there four different categories for each box? Commented Mar 29, 2019 at 13:47
• @Areeb Yeah, four for the first one and different four for the second one.
– Jafe
Commented Mar 29, 2019 at 13:48

I believe that kovacsur has the first box. Borrowing from their answer (thanks, @kovacsur!):

lithium BATTERY, alkaline BATTERY, BATTERY acid, car BATTERY = BATTERY
sandSTORM, snowSTORM, brainSTORM, hailSTORM = STORM
BLOOD money, BLOOD pressure, BLOODbath, BLOODhound = BLOOD
SOLAR eclipse, SOLAR system, SOLAR panel, SOLAR wind = SOLAR

The word I'd associate with all of their found words is

CELL: blood cell, solar cell, cell battery, storm cell.

Then:

BIcameral, BImonthly, BIlingual, BIpedal = BI
seaWATER, still WATER, holy WATER, mineral WATER = WATER (thanks, @kovacsur!)
half LIFE, wildLIFE, LIFEboat, shelf LIFE = LIFE (thanks, @kovacsur!)
MOTORhome, hot MOTOR, MOTOR oil, MOTORway = MOTOR

This means that the second word is

CYCLE: biCYCLE, water CYCLE, life CYCLE, and motorCYCLE.

The two words from this puzzle are

• That sounds reasonable. Commented Mar 29, 2019 at 14:48
• Oh, I was too late, it seems. Well done! :) Commented Mar 29, 2019 at 15:09
• Thank you! Great start on the solving! Good teamwork, @kovacsur :) Commented Mar 29, 2019 at 15:14
• You have the correct answer, although somehow the grouping is a bit different than I intended... I had rot13(fgvyy yvsr, zbgbeobng, naq ubg jngre)! :P
– Jafe
Commented Mar 29, 2019 at 20:37

Let's see if I can get the formatting right...

lithium alkaline acid car battery
sand snow brain hail storm
money pressure bath hound blood
eclipse system panel wind solar

That said,

solar-battery bloodstorm sounds a bit of a stretch, though.
Alright, I am fairly certain that the word for the first box is plexus. Update: nope, it is indeed cell.

Second box:

lingual monthly cameral pedal bi
sea still holy mineral water
half wild boat shelf life
home hot oil way ???

Still not sure about the last group, but the second word is

cycle

Making the complete solution

cell cycle

• No problem! I think you have the correct four words, you just need to find another word that relates to the four bolded words that you already found. Great start! Commented Mar 29, 2019 at 14:43

Box 1:

1. Batteries: car, acid, lithium, alkaline
2. Weather: hail, snow, pressure, wind
3. Human: system, bath, money, panel
4. Nature: sand, hound, eclipse, brain