Get the co-sister-in-lawmug. Bro, I was about to get with this chick but she fucked Chad.
Dude, never fuck your eskimo sister in laws. That's almost incest.
Dude, never fuck your eskimo sister in laws. That's almost incest.
by Callmedad42 July 22, 2017
Get the eskimo sister in lawmug. 
Get the half-co-sister-in-lawmug. 
The sacred sister law states that “If you find news or information that makes you feel uncomfortable, you must share it to your sister”.
The sacred sister law: Brit and char are sisters. Brit found a video about an onion that made her feel uncomfortable. Brit shared the video to Char.
by Shhhitsbrit November 21, 2022
Get the The sacred sister lawmug. My co-sister-in-law is a good person.
by Elivaldeq November 24, 2019
Get the co-sister-in-lawmug. Standard Sister-in-Law Unit
noun
*| \ ˈsta-ndərd ˈsi-stər-in-ˌlȯ yü-nət *
Abbreviation: SSILU
Symbol: 𝓢 or SIL
Definition:
An unofficial unit of mass equal to 300 pounds (136.08 kilograms), used to simulate high-risk, real-world human load scenarios in mechanical, structural, and transportation systems. The SSILU is commonly applied to test the failure thresholds of furniture, vehicle seats, elevators, bicycles, airline cabins, and public patience.
Etymology:
Originated in post-war American slang, the term is derived from the stereotype of a loud, heavyset female relative—often portrayed as emotionally volatile and structurally compromising—whose presence tests both family dynamics and infrastructure load-bearing capacity. While non-literal, the “sister-in-law” archetype evokes maximum physical and psychological mass concentration in civilian environments.
Technical Classification:
Measurement Type: Anthropomorphic Load Unit
Mass: 300 lbs (≈ 136.08 kg)
Field Use: Structural stress testing, emergency engineering simulation
Design Benchmark: Most consumer goods are not rated past 0.8 SSILU
noun
*| \ ˈsta-ndərd ˈsi-stər-in-ˌlȯ yü-nət *
Abbreviation: SSILU
Symbol: 𝓢 or SIL
Definition:
An unofficial unit of mass equal to 300 pounds (136.08 kilograms), used to simulate high-risk, real-world human load scenarios in mechanical, structural, and transportation systems. The SSILU is commonly applied to test the failure thresholds of furniture, vehicle seats, elevators, bicycles, airline cabins, and public patience.
Etymology:
Originated in post-war American slang, the term is derived from the stereotype of a loud, heavyset female relative—often portrayed as emotionally volatile and structurally compromising—whose presence tests both family dynamics and infrastructure load-bearing capacity. While non-literal, the “sister-in-law” archetype evokes maximum physical and psychological mass concentration in civilian environments.
Technical Classification:
Measurement Type: Anthropomorphic Load Unit
Mass: 300 lbs (≈ 136.08 kg)
Field Use: Structural stress testing, emergency engineering simulation
Design Benchmark: Most consumer goods are not rated past 0.8 SSILU
“She hit the fitting room like a breaching whale—1 Standard Sister-in-Law Unit (SSILU) 300lbs in full stride, swatting children aside and hollering ‘THESE SIZES RUN SMALL!!! while nearby store associates quietly begged for a swift death
by Ludwig Von Snooterman June 7, 2025
Get the Standard Sister-in-Law Unit (SSILU) [300lbs]mug.