[im-pur-mee-uh-buh l] /ɪmˈpɜr mi ə bəl/
not permeable; impassable.
Chemistry, Geology. (of porous substances, rocks, etc.) not permitting the passage of a fluid through the pores, interstices, etc.
(of a substance) not allowing the passage of a fluid through interstices; not permeable
1690s, from French imperméable, from Late Latin impermeabilis, from assimilated form of in- “not, opposite of” (see in- (1)) + permeabilis (see permeable).
impermeable im·per·me·a·ble (ĭm-pûr’mē-ə-bəl)
Impossible to permeate; not permitting passage.
im·per’me·a·bil’i·ty or im·per’me·a·ble·ness n.
Relating to a material through which substances, such as liquids or gases, cannot pass. Some substances, such as some types of contact lenses, are permeable to gas but impermeable to liquid.
[im-per-mis-uh-buh l] /ˌɪm pərˈmɪs ə bəl/ adjective 1. not or allowable; unallowable. /ˌɪmpəˈmɪsɪbəl/ adjective 1. not permissible; not allowed adj. 1814, from assimilated form of in- “not, opposite of” (see in- (1)) + permissible.
1. . 1. impersonal 2. impersonally
adj. “unrecorded, without written authority,” 1832, used only with right. From assimilated form of Latin in- “not, opposite of” (see in- (1)) + perscribere “to write down.”
/ˌɪmpəˈskrɪptɪbəl/ adjective 1. not supported by written authority