1) Enjoying oneself 2) Formation 3) Rifling 4) Shaping 1) Rifling 
erosion of a boiler's plates from the internal water space, particularly where there is a step inside the shell. This was a problem for early boilers made from lapped plates rather than butted plates, and gave rise to many boiler explosions. In later years it was a problem for the non-circular water drums of Yarrow boilers.
• (n.) The act of forming a groove or grooves; a groove, or collection of grooves.
Shearing fur in "stripes" of alternating widths and depths The result is similar to corduroy; the stripes can be wide or narrow Also called cording
Groov'ing noun The act of forming a groove or grooves; a groove, or collection of grooves. 
[n] - the cutting of spiral grooves on the inside of the barrel of a firearm
rifling noun the cutting of spiral grooves on the inside of the barrel of a firearm
The process used to cut slots into a concrete pavement surface to provide channels for water to escape beneath tires and to promote skid resistance.