A collapsible bottle defining a variable volume internal compartment for containing a fluid to be dispensed from a fluid dispenser , the collapsible bottle comprising: a first exterior wall ; a second exterior wall ; a third exterior wall ; and a neck that extends along an axis away from the third exterior wall , the neck having an opening in fluid communication with the internal compartment ; wherein the internal compartment contains an initial volume of the fluid when the collapsible bottle is in an initial configuration; wherein, as the fluid is dispensed from the collapsible bottle , the collapsible bottle deforms from the initial configuration towards a collapsed configuration, the internal compartment containing a smaller volume of the fluid when in the collapsed configuration than when in the initial configuration; wherein the first exterior wall is thinner than the second exterior wall ; wherein the first exterior wall is further from the axis than the second exterior wall is from the axis when the collapsible bottle is in the initial configuration; and wherein the first exterior wall moves towards the axis as the collapsible bottle deforms from the initial configuration towards the collapsed configuration; wherein the first exterior wall and the second exterior wall are each intersected by a first plane that contains the axis ; wherein the collapsible bottle has a fourth exterior wall and a fifth exterior wall that are each intersected by a second plane that contains the axis , the second plane being perpendicular to the first plane ; wherein the collapsible bottle has a sixth exterior wall that is intersected by the axis ; and characterized in that the fourth exterior wall , the fifth exterior wall , and the sixth exterior wall have a reinforcement structure that resists deformation of the fourth exterior wall , the fifth exterior wall , and the sixth exterior wall as the collapsible bottle deforms from the initial configuration towards the collapsed configuration. a first exterior wall ; a second exterior wall ; a third exterior wall ; and a neck that extends along an axis away from the third exterior wall , the neck having an opening in fluid communication with the internal compartment ; wherein the internal compartment contains an initial volume of the fluid when the collapsible bottle is in an initial configuration; wherein, as the fluid is dispensed from the collapsible bottle , the collapsible bottle deforms from the initial configuration towards a collapsed configuration, the internal compartment containing a smaller volume of the fluid when in the collapsed configuration than when in the initial configuration; wherein the first exterior wall is thinner than the second exterior wall ; wherein the first exterior wall is further from the axis than the second exterior wall is from the axis when the collapsible bottle is in the initial configuration; and wherein the first exterior wall moves towards the axis as the collapsible bottle deforms from the initial configuration towards the collapsed configuration; wherein the first exterior wall and the second exterior wall are each intersected by a first plane that contains the axis ; wherein the collapsible bottle has a fourth exterior wall and a fifth exterior wall that are each intersected by a second plane that contains the axis , the second plane being perpendicular to the first plane ; wherein the collapsible bottle has a sixth exterior wall that is intersected by the axis ; and characterized in that the fourth exterior wall , the fifth exterior wall , and the sixth exterior wall have a reinforcement structure that resists deformation of the fourth exterior wall , the fifth exterior wall , and the sixth exterior wall as the collapsible bottle deforms from the initial configuration towards the collapsed configuration. <EOS>